Last updated 5/14/03 |
Growth Regulators for Golf Courses
With the excess rain and difficult mowing schedules, the turfgrass growth regulators used on some golf courses have really shined so far this year. Proxy plus Primo, in particular, has worked really well for Poa seedhead reduction and limiting vertical growth. For the cost of this combination per acre, one app easily paid for itself the last few weeks in reduced labor for mowing, clipping collection, and/or blowing clippings. There have been some changes with the growth regulators with the addition of Proxy to the market and the reappearance of Cutless. We are still learning about all these products, but following is a summary of my current recommendations for golf courses based on research and what I’ve seen on and heard from golf courses.
Early Spring:
Proxy plus Primo for seedhead reduction on Poa and plus vertical growth regulation on all species. Limiting seedheads is always tricky, but this combination has shown tremendous potential. Proxy is not labeled for greens, however. Embark T&O is still used often for seedhead reduction but that is not labeled for greens either.
Summer:
Primo for growth reduction on fairways and greens, plus it tends to make Poa a smidge more stress tolerant. Primo is probably the most consistent product among species and cultivars for growth management. No matter what you may hear, Primo does not favor creeping bentgrass over Poa and so is no good for conversion away from Poa. Trimmit or Turf Enhancer are the weapons of choice for this and using these throughout the summer gives the bentgrass a fighting chance over the Poa. I have seen this work best on fairways where the mowing heights will allow bentgrass to be competitive, but it also shows promise on greens the farther south you go in IN.
Fall:
On areas where you want to limit Poa, continue the Trimmit or Turf Enhancer into late September but be careful once the threat of frost starts.
Again, we are learning the in’s and out’s of the growth regulators, tank-mix benefits, precautions, etc. What may work in one region of the country may not work in another. Worse yet, what works on one course may not work on another a mile away. My advice is do your own testing on a single fairway or green, and keep abreast of Turf Tips and the other electronic information available.
Zac Reicher, Associate Professor/Turfgrass Extension Specialist
Send corrections, suggestions, and comments to biehlj@purdue.edu